Facebook CEO Mark Zuckerberg speaks at the company’s headquarters in Menlo Park, Calif., on Thursday. Zuckerberg says the company is not building a phone or an operating system. Rather, Facebook is introducing a new experience for Android phones.

MENLO PARK, Calif. — With its new “Home” on Android gadgets, Facebook aims to put its social network at the center of people’s mobile experiences.

If users choose to download Facebook’s Home software starting on April 12, the social network will become the hub of their Android smartphones. A phone from HTC that comes pre-loaded with Home will also be available starting that day, with AT&T Inc. as the carrier.

The idea behind the software is to bring Facebook content right to the home screen, rather than requiring users to check apps. “Home” comes amid rapid growth in the number of people who access Facebook from phones and tablet computers. Of its 1.06 billion monthly users, 680 million log in to Facebook using a mobile gadget.

The service is part of Facebook’s move to shift its users’ focus from “apps and tasks” to people, said CEO Mark Zuckerberg during Home’s unveiling at the company’s Menlo Park, Calif., headquarters on Thursday.

The new product, which resides on the home screen of Android phones, is a family of apps designed to help people share things with their Facebook friends. Rather than seeing a set of apps for email, maps and other services when they first turn on their phones, users will be greeted with photos and updates from their Facebook feeds. There will be ads too, eventually.

“We think this is the best version of Facebook there is,” Zuckerberg said.

Zuckerberg says users can have an experience on Android phones that they can’t have on other platforms. That’s because Google makes the software available on an open-source basis, allowing others to adapt it to their needs.

Recognizing that text messaging is one of the most important tasks on a mobile phone, Facebook also showed off a feature called “chat heads.” This lets users communicate with their friends directly from their phone’s home screen — without opening a separate app.

The move that coincides with rapid growth among the number of users who access the social network from smartphones and tablet computers and Facebook’s aim to evolve from its Web-based roots into a “mobile-first” company.

“What Facebook wants is to put itself at the front of the Android user experience for as many Facebook users as possible and make Facebook more elemental to their customers’ experience,” said Forrester analyst Charles Golvin.

The new Home service won’t be available on Apple’s iPhone and iPad devices. Apple’s iOS and Mac operating systems include features that integrate Facebook’s services, but Zuckerberg says doing something like Home would require a closer partnership.

Apple had no immediate comment.

The deeper mobile integration will likely help Facebook to attract more mobile advertisers. Though mobile ads were a big concern for Facebook’s investors even before the company’s initial public offering last May, some of the worry has subsided as the company muscles its way into the market.

Last year, Facebook began showing ads to its mobile audience by shoehorning corporate-sponsored content into users’ news feeds, which also include updates from friends and brands they follow. Facebook now faces the challenge of showing people mobile ads without annoying or alienating them.

The mobile advertising market is growing quickly, thanks in large part to Facebook and Twitter, which also entered the space in 2012. Research firm eMarketer expects U.S. mobile ad spending to grow 77 percent this year to $7.29 billion, from $4.11 billion last year.

EMarketer said Wednesday that it expects Facebook Inc. to reap $965 million in U.S. mobile ad revenue in 2013. That’s about 2.5 times the $391 million in 2012, the first year that Facebook started showing mobile ads. Clark Fredricksen, vice president at eMarketer, says “there are some clear reasons why a deeper integration with mobile operating systems and handsets make sense for Facebook. At the end of the day, the more deeply Facebook can engage consumers, no matter what device or operating system or handset,” the better.

Facebook’s stock rose 80 cents, or 3.1 percent, to $27.05 in afternoon trading following the announcement. It’s still 23 percent below its initial public offering price of $35.